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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
8
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pubmed:dateCreated |
1989-8-17
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pubmed:abstractText |
Proton and phosphorus NMR studies are reported for two complementary nonanucleotide duplexes containing acyclic abasic sites. The first duplex, d(C-A-T-G-A-G-T-A-C).d(G-T-A-C-P-C-A-T-G), contains an acyclic propanyl moiety, P, located opposite a deoxyadenosine at the center of the helix (designated APP 9-mer duplex). The second duplex, d(C-A-T-G-A-G-T-A-C).d(G-T-A-C-E-C-A-T-G), contains a similarly located acyclic ethanyl moiety, E (designated APE 9-mer duplex). The ethanyl moiety is one carbon shorter than the natural carbon-phosphodiester backbone of a single nucleotide unit of DNA. The majority of the exchangeable and nonexchangeable base and sugar protons in both the APP 9-mer and APE 9-mer duplexes, including those at the abasic site, have been assigned by recording and analyzing two-dimensional phase-sensitive NOESY data sets in H2O and D2O solution between -5 and 5 degrees C. These spectroscopic observations establish that A5 inserts into the helix opposite the abasic site (P14 and E14) and stacks between the flanking G4.C15 and G6.C13 Watson-Crick base pairs in both the APP 9-mer and APE 9-mer duplexes. The helix is right-handed at and adjacent to the abasic site, and all glycosidic torsion angles are anti in both 9-mer duplexes. Proton NMR parameters for the APP 9-mer and APE 9-mer duplexes are similar to those reported previously for the APF 9-mer duplex (F = furan) in which a cyclic analogue of deoxyribose was embedded in an otherwise identical DNA sequence [Kalnik, M. W., Chang, C. N., Grollman, A. P., & Patel, D. J. (1988) Biochemistry 27, 924-931]. These proton NMR experiments demonstrate that the structures at abasic sites are very similar whether the five-membered ring is open or closed or whether the phosphodiester backbone is shortened by one carbon atom. Phosphorus spectra of the APP 9-mer and APE 9-mer duplexes (5 degrees C) indicate that the backbone conformation is similarly perturbed at three phosphodiester backbone torsion angles. These same torsion angles are also distorted in the APF 9-mer but assume a different conformation than those in the APP 9-mer and APE 9-mer duplexes.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/DNA,
http://linkedlifedata.com/resource/pubmed/chemical/Deoxyadenosines,
http://linkedlifedata.com/resource/pubmed/chemical/Ethane,
http://linkedlifedata.com/resource/pubmed/chemical/Propane,
http://linkedlifedata.com/resource/pubmed/chemical/Protons
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
18
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pubmed:volume |
28
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3373-83
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2545258-Base Composition,
pubmed-meshheading:2545258-Binding Sites,
pubmed-meshheading:2545258-DNA,
pubmed-meshheading:2545258-Deoxyadenosines,
pubmed-meshheading:2545258-Ethane,
pubmed-meshheading:2545258-Magnetic Resonance Spectroscopy,
pubmed-meshheading:2545258-Molecular Structure,
pubmed-meshheading:2545258-Nucleic Acid Conformation,
pubmed-meshheading:2545258-Propane,
pubmed-meshheading:2545258-Protons
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pubmed:year |
1989
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pubmed:articleTitle |
NMR studies of abasic sites in DNA duplexes: deoxyadenosine stacks into the helix opposite acyclic lesions.
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pubmed:affiliation |
Department of Biochemistry and Molecular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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